Patients who suffer from obstructive sleep apnea can use continuous positive airway pressure (CPAP) therapy to maintain the upper airway open while they are asleep. CPAP therapy is applied to the patient using a mask, tubing, and a flow generator. All of these components encompass the air delivery system provided to the patient.
One problem for patients who undergo CPAP therapy is irritation and skin ailments, e.g., sores, caused by wearing a mask. The problem is a result of the mask cushion compressing or applying pressure to the patient's skin in a similar region for a prolonged length of time. Blood capillaries may be squashed or impinged upon which may cause a blockage or partial blockage to circulation. This may result in inflammation and/or redness of the skin and/or facial numbness. These problems may cause a patient to cease therapy.
A known solution includes buying two or more different masks and wearing them alternately. Another known solution includes switching between two different styles of mask, e.g., switch between a full-face mask and a nasal mask or switch between a nasal cushion and nasal pillows. Yet another known solution includes repositioning the mask on the patient's face if the patient wakes up during the night. These solutions have several drawbacks, e.g., requires the purchase of multiple masks and/or prevents patient from a full night of sleep.
Another problem is sweat or humidification caused by wearing a mask. The sweat or humidification can block the patient's skin ducts, which may cause irritation. Moisture held against the skin can also soften the skin rendering it more susceptible to damage. Therefore, it is desirable to allow moisture removal from the skin surface.
Another problem patients have with masks is that they are uncomfortable, and it can be difficult for patients to relax when wearing one. If a patient cannot relax enough to fall asleep, then the mask is ineffective as treatment for sleeping disorders as it is preventing the patient from having a full nights sleep.
Another problem with masks is mask leak. Leaks between the cushion and the patient's skin can be generated after the patient has fallen asleep due to the patient's movements. These leaks may cause the mask to stop delivering treatment by reducing the mask pressure and/or by waking the patient. Either of these occurrences will result in the patient not receiving a good nights sleep.
Leaks tend to occur at specific regions of the cushion seal. It is known that additional pressure to stop the leaks may be applied by tightening headgear straps. However, this approach tends to tighten the entire cushion against the patient's face, which can lead to discomfort or sores.
Thus, there is a need for an improved patient interface that does not suffer from the above-mentioned drawbacks.